Not Applicable.
1. Field of the Invention
The invention relates most generally to end cap devices used to act as closure members for corrugated conduits. More particularly this invention relates to a specially designed end cap which provides enhanced resistance to tensile forces against the end cap, while providing an angled entry port for connecting hoses. Even more particularly the invention relates to a specially designed end cap that fits onto a corrugated cylindrical conduit which has ridges, channels and grooves over which a plurality of tabs provides durable connection between the end cap and the corrugated conduit by fitting securely between the corrugated conduit ridges, channels, or grooves. And further the invention provides strength-enhancing and stress reduction characteristics, primarily comprising selective thickening of the capping material, selective placement of ribbing, and non-tearing fingers at the entry point of a sewer and drainpipe hose.
2. Description of Related Art
There are many devices used in terminating pipe and/or conduit. In most instances, the devices are not designed for enhancing strength in both the cap and the connection between the cap and the conduit, but only for providing a closure sufficient to restrict the entry of dirt and other possible contaminants. It would be advantageous to have an end cap especially for closing corrugated pipe which emphasizes or addresses the multiple facets of an easy-to-use, versatile, and highly functional closure.
There is nothing currently available which satisfies these needs and objectives. However, the invention disclosed herein does meet all of these objectives. No prior art of which applicant is aware is as effective and as efficient as the instant end cap. Clearly, the instant invention provides many advantages over the prior art known by applicant. Again it is noted that none of the prior art meets the objects of the end cap as used in septic and waste water treatment in a manner like that of the instant invention. None of them is as effective and as efficient.
It is also important to note that the use of the end caps of the present invention permits the easy terminating of conduit sections and more particularly the angular insertion of connecting hoses to corrugated plastic septic pipe used in septic systems. The end caps may be used with standard forms of corrugated pipe and with special designs of corrugated pipe as long as the pipe contains some form of circumferential ribbing or perforation.
Prior art in the field of end caps mostly discloses an end cap having a separate clamping mechanism, which is different from the connecting tabs of the present invention. Prior art that does not require a separate clamp, such as U.S. Pat. No. 3,711,632, requires hinged sections, not a single-piece closure arrangement ""632 discloses an end fitting comprising a pair of sections for corrugated tube that is used for holding electrical leads. In claim 2, claimed sections are hinged and connected together by releasable latching having a catch member on one of the sections and a latch member on the other. One end of each section has an arcuate and circumferentially and radially inwardly extending rib that is adapted to be received between adjacent corrugations of the corrugated tube to substantially lock the end fitting against relative movement axially of the tube. This invention requires hinged sections that are disposed upon a piece of corrugated pipe. In a preferred form, this disclosure relates to an end fitting for use for a flexible, plastic, axially slit, corrugated tube for housing a plurality of electrical leads. The end fitting includes a pair of sections of generally semicircular cross-sectional shape which are integrally hinged by a hinge means along their adjacent side edges thereof and which are foldable about the hinge means to a closed position in which they surround the corrugated tube, and a releasable latching means for latching the sections together in their closed position. One end portion of each of the sections has arcuate, circumferentially and radially inwardly extending ribs which are adapted to be received between adjacent ones of the corrugations of the corrugated tube to lock the end fitting against relative movement axially of the tube, and the other end portions of the sections each have a radially inwardly extending member, the inwardly extending members defining a chordially extending barrier when the sections are in their closed positions so as to position the leads within the end fitting.
U.S. Pat. No. 3,713,463 discloses a closure member for sealing a pipe that is a cap of rubber with a cylindrical skirt and ridges on the inner circumference to engage the outer periphery of the pipe. As claimed, this device requires a clamp to surround and constrict the skirt against the outer periphery of the pipe. The closure member comprises a cylindrical cap of rubber or other elastomeric material, the cap being closed at one end and having inwardly and circumferentially extending ridges around the inner periphery of its skirt to engage the outer periphery of the pipe. A clamp surrounds the skirt and is adapted to constrict the skirt against the pipe to seal the latter.
U.S. Pat. No. 4,112,979 discloses an end cap for a pipe, having a tubular sleeve with spaced tongues extending substantially parallel to the axis of the sleeve. The sleeve is surrounded by a clamping ring that is fastened to the sleeve by a sealing ring. The end cap is formed with a sleeve of plastics material closed at a first end by a wall and having tongues formed integrally with the sleeve on the opposite or second end. These tongues fit in openings in a plastics clamping ring at the second end of the sleeve and engage with a side of the ring to prevent removal of the clamping ring. The clamping ring holds a sealing ring of rubber material around the inside of the sleeve for sealing engagement with the pipe fitted into the sleeve through the second end of the latter.
U.S. Pat. No. 5,758,693 discloses a sewage hose end cap that can be placed on a spiraling hose end and secured tightly by a clamp mechanism. The end cap for a flexible hose includes a depending pivotable member attached to an outer wall. The pivotable member can be swung upwardly between the inner and outer walls of the end cap to secure the end of a flexible hose therein. The end cap is integrally formed such as by molding from a medium density polymeric material such as polyethylene and includes an integral clamp mechanism to insure retention of a flexible hose therein. This end cap is not suitable for corrugated conduit piping.
None of these patents provides for a light-weight, yet durable, strong, and easy to engage end cap device for conduit/pipe particulary corrugated conduit. Many require extra clamps and steps for installation, and none has the additional sewer and drainpipe hose feature.
In the most fundamental aspect of the present invention, there is provided an end cap device for quickly, effectively, simply, safely and economically providing closure to the end of a section of conduit piping. The preferred end cap consists of a formed, preferably plastic, cap with an end piece that curves into a skirt which is diametrically sized to fit snugly over a conduit section, preferably a corrugated conduit section. Within the end cap, integral with the skirt, and hingedly attached, is a plurality of tabs whose unattached ends contain triangular wedges which protrude towards the outer surface of the conduit (and towards the interior of the end cap) and which can be lodged within recesses (valleys of the corrugations) of the corrugated conduit as the end cap is pressed onto the corrugated conduit or pressed onto a smooth walled conduit wherein a groove or valley is created at a distance from the open end so as to be mateable with the connection/connecting tabs.
Each triangular wedge causes the tab to which it is connected to swing (or be pushed) away from the corrugated conduit until the wedge reaches a recess (valley) between the protrusions (peaks) of the corrugated conduit. At that time, the wedge""s shelf-like edge moves into adjacency with the lower edge of the protrusion (peak) that the wedge has just been pushed past. If the end cap is pressed again, the tab and wedge, when encountering the next corrugated conduit protrusion, swing (are pushed) away again from the corrugated conduit outer surface until, once again, a recess between protrusions is reached, where once again the wedge is lodged and the end cap is fixed in closure position on the corrugated conduit.
On the end piece can be stamped or perhaps cut out one or more holes to receive a sewer and/or drainpipe hose. If an end cap is manufactured to accept a sewer and drainpipe hose, in the preferred embodiment, the cut out hole is fitted around its circumference with flexible fingers that can bend either towards the inner or the outer surface of the end cap to accommodate the insertion of a sewer and drainpipe hose. In the preferred embodiment, the fingers are integrally and hingedly attached to a continuous ring. At the hinge point of each finger, and on either side of each finger, is drilled an enlargement or hole to reduce the stress on the finger as it swings back and forth. This stress reduction mechanism increases the structural durability of the finger assembly.
An additional novel feature of this invention involves additional strengthening due to the addition of strengthening ribs or other devices that increase structural durability while maintaining a light-weight and easy to handle end cap. Anywhere on the end cap, but in particular in the vicinity of or surrounding areas on the end cap that will experience increased stress in the course of usage, are ribs which comprise a band of thickened material. In the preferred embodiment, the thickened material takes the cross-sectional shape of an apex-flattened equilateral triangle, although any shape is possible. The base of the triangle is flush with the surface of the end cap. In the preferred embodiment, the end cap is thickened in the area of the sewer and drainpipe hose insertion holes or recesses. The thickened material traverses the end cap in the shape of an hourglass, in the preferred embodiment, in which the thin area of the hourglass runs between the point at which the two example sewer and drainpipe hose entry points are most closely tangential. The thickened material could inscribe any shape, such as encircling the sewer and drainpipe entry holes. In addition, strengthening ribs could also be included to surround the openings in the circumferential skirt where the connection tabs are located.
Another novel feature of the instant end cap is the arcuate shape of the end piece which is, in the preferred embodiment, convex towards the point at which closure pressure would be applied to the end cap. The apex of the arced end piece can form any angle with the vertical. In the preferred embodiment, however, and where there is accommodation for sewer and drainpipe hoses, the angular displacement from the vertical axis parallel with the apex of the end piece sets the entry angle of the sewer and drainpipe hose which determines the level at which the corrugated conduit may be filled before its contents enter and/or leave the sewer and drainpipe. In addition to providing for off-axis entry of sewer and drainpipe hoses, the arced end piece provides for additional structural integrity, especially during the pressure of inserting the end cap onto the end of the corrugated conduit. Further, the arced end piece increases the rigidity and structural integrity of the end cap during the insertion and extraction of sewer and drainpipe hoses.
It is therefore a feature of the present invention to provide an end cap for a conduit, preferably a corrugated conduit, that can be immovably positioned onto a corrugated conduit through lodging of at least one tab, but preferably a plurality of tabs which are integral to the end cap, into the recesses or valleys of the corrugated conduit.
Another feature of the present invention is to provide an end cap that is selectively strengthened through integral thickened ribbing in areas that experience enhanced stress during the usage of the end cap.
Another feature of the present invention is to provide an end cap that allows for insertion and removal of sewer and drainpipe hoses of various diameters through pre-punched holes in the end piece of the end cap.
A further feature of the present invention is to provide an end cap in which insertion points for sewer and drainpipe hoses are circumferentially fitted with a plurality of flexible, tear-resistant fingers to allow easy insertion of sewer and drainpipe hoses and resistance to hose movement within the insertion point.
A yet still further feature of the present invention is to provide an end cap with a convex curved end piece that allows for additional strength of the end cap and for off-axis positioning of sewer and drainpipe hoses.